"The effects of tropical deforestation on
climate go well beyond carbon," says Professor Deborah Lawrence,
"[it] causes warming locally, regionally, and globally, and it
changes rainfall by altering the movement of heat and
These are the conclusions of a worldwide study into
the deforestation of tropical rainforests, which shows that cutting
down trees can have immediate impacts on the climate and put
agricultural productivity at risk.
Rainforests are more than just a carbon
Deforestation and land use change account for
11 per cent of global carbon dioxide
emissions. But the new research finds that cutting
down trees doesn't only affect the
carbon they lock up.
The research, published in Nature Climate
Change, reviews academic studies on deforestation
tropical rainforests in the Amazon basin,
central Africa, and southeast Asia. Many of the studies use climate
models to simulate what happens if you remove these forests
completely, and they suggest that deforestation in the tropics can
affect the climate on the other side of the world.
The map below shows how far-reaching some of
these potential impacts are. The triangles show areas where
rainfall is expected to decrease because of tropical deforestation,
and the circles show areas of increase. The colours indicate the
link to where the deforestation occurs.
So the models suggest deforestation in the
Amazon, for example, can reduce rainfall over the US Midwest and
even in northeast China. Deforestation in central Africa can cause
a drop in rainfall in southern Europe, and loss of trees in
southeast Asian can bring wetter conditions in southern Europe and
the Arabian Peninsula.